Wireless subscriber managing storage of HARQ packets

#The invention relates generally to wireless communications. More particularly, the invention relates to managing storage of HARQ packets.

#Transmission of data packets over wired and wireless links needs to be fast and reliable. Speed requirements are set by seemingly ever-increasing data transfer rates, and quality of service requirements are set by increasing system needs for accuracy in transmissions.

#Digital data transmissions over wired and wireless links sometimes may be corrupted, for instance, by noise in the link or channel, by interference from other transmissions (e.g., radio), or by environmental factors related to, for example, the speed, direction, location and requests between transmitting and receiving units. Even with clear communication channels (i.e., channels with limited corruption), which lend themselves to the high data rates, it may not be possible to appropriately decode the data stream with the requisite error rates. Digital data transmissions may also be limited by an inability of the receiving or transmitting equipment to appropriately encode and decode the data stream at the speeds desired with the requisite error rates.

#FIG. 1 shows an example of a wireless receiver system that stores HARQ packets.

#FIG. 2 shows a WiMax downlink and uplink frames that includes variable sized data bursts that contain the HARQ packets.

#FIG. 3 shows an example of a wireless receiver system that stores variable size HARQ packets while operating in an aggregation mode.

#Methods and apparatuses for managing HARQ memory are disclosed. Embodiments of the methods and apparatuses provide efficient storage of HARQ bursts that fail an error check.

#FIG. 1 shows an example of a wireless receiver (generally a transceiver, for example, a WiMax subscriber) that stores HARQ packets. Transmission signals are received through a receiver antenna 105, and demodulated by demodulation electronics 110. For an embodiment, the demodulated signal includes HARQ burst log likelihood ratios (LLRs). For the description here, HARQ burst LLRs and HARQ packets may be used interchangeably. Some or all of the HARQ burst LLRs from one HARQ burst transmission may be combined with the HARQ burst LLRs for previous transmission of the same HARQ burst.

#For WiMax signals, each HARQ burst is associated with a channel identifier (ACID) that identifies the burst within a WiMax frame. If a HARQ burst having a specific ACID is received for the first time, the HARQ burst LLRs are decoded by a burst decoder 130. For one embodiment, the HARQ burst LLRs are also stored in HARQ memory 160. The decoded HARQ burst LLRs are then checked for errors by a burst CRC checker 140. If the HARQ burst LLRs pass the CRC, then the decoded burst is considered successfully received. The decoded data is passed to the next element of the receiver.